1. Field of the Invention
This invention relates generally to electrical wiring installations and more particularly to a liquid tight coupling for splicing lengths of non-metallic electrical conduit.
2. Antecedents of the Invention
Various types of couplings have been proposed heretofore for use in conjunction with non-metallic electrical conduit. Due to deficiencies in construction, cost, or labor considerations, it was often more feasible to select or cut a conduit length to the exact size needed, rather than to splice lengths of conduit for a specific electrical installation. This practice resulted in unnecessary excess scrap which required environmentally sound disposal.
It has been generally found that couplings having compression type fittings were unsuitable for use in splicing lengths of non-metallic electrical conduit, due to the multiplicity of parts as well as material and labor costs involved in effecting a splice. Push type couplings formed of a plurality of annular barbs were also found unsuitable, due to deficiencies in joint tensile strength.
There was a need, therefore, for a low cost, one-piece, lightweight coupling for non-metallic electrical conduit which would be both simple to use and provide ample resistance to separation.